8S5] Machinery and Labor 87 



ing day is worth less than that of the second, or of the 

 third, etc. But after the sixth or seventh hour the 

 workman becomes increasingly less efficient. More- 

 over, if he works beyond his strength in any one day, 

 and still more, if he works beyond his strength for any 

 considerable length of time, he loses vitality ; and loss 

 of vitality, whatever may be the determining cause, 

 means, inevitably, the degradation of the workman and 

 a permanently decreased efficiency. 1 



The employer who is seeking the highest net return 

 from an investment in labor should, therefore, if he is 

 wise, be guided by a very different rule, in fixing the 

 working-day for a man, from that which he should 

 follow in fixing the length of the working-day for a 

 machine. 



If the term of employment is for a day only, and 

 fresh workmen can be secured for each succeeding day, 

 it may pay the employer to crowd his employees, to the 

 utmost limit of their strength throughout, perhaps, the 

 full twenty-four hours of the day. But if the term of 

 employment is for a year, or for life, with no chance of 

 getting a substitute, then it will, ordinarily, 2 pay an 

 employer to be more saving of his employees' vitality. 

 He must now look to the preservation of the health and 

 strength of his employees for the longer period of em- 

 ployment. It is only in this way that the employer 

 can secure the highest net return on his investment. 

 We know, however, that employers are sometimes both 



i Walker: Wages, pp. 81-88. 



2 " Slave-labour, under an intelligent profit monger, may require 

 provision to be made for a full working life, though even in slavery 

 it may sometimes pay to use up a slave by intense toil during a 

 shorter period." John A. Hobsou : The Economies of Distribution, 

 p.. 162. 



